Re: Can't enable DMA

[Shyamal Prasad <shyamal.prasad@sbcglobal.net>]

    "Andrew" == Andrew McGuinness <andrew@arobeia.co.uk> writes:

    Andrew> Aaron wrote:
    >> 
    >> I've been having this same problem, but apparently my VIA
    >> version doesn't match 82CXXX, so I'm completely dead in the
    >> water for DMA (I know, VIA is bad). I want to buy a PCI IDE

    Andrew> You need a newer kernel.  Stock 2.4.18 wasn't up-to-date
    Andrew> with VIA agp chipsets -- Red Hat always patch their
    Andrew> kernels with driver updates, which is why your Red Hat
    Andrew> system worked.

While this is true I'd be interested in what AGP has to do with DMA. I
have a KT266A based motherboard (Soyo K7V Dragon+), and I run Debian's
2.4.18-k7, and DMA works great for me....???

Perhaps it is because I do not load the agpgart module. I don't use
AGP because I use a $20 Mach64 card to throw a lot of pixels on to my
21 inch monitor for emacs and xterms. No fancy graphics and stuff. Is
it the act of turning on AGP that causes the 2.4.18 kernel to make DMA
unavailable?

shyamal@rattler:~$ dmesg | grep agp
shyamal@rattler:~$ dmesg | grep KT
shyamal@rattler:~$ /sbin/lsmod | grep agp
shyamal@rattler:~$ lspci
00:00.0 Host bridge: VIA Technologies, Inc. VT8367 [KT266]
00:01.0 PCI bridge: VIA Technologies, Inc. VT8367 [KT266 AGP]
00:0e.0 Multimedia audio controller: C-Media Electronics Inc CM8738 (rev 10)
00:11.0 ISA bridge: VIA Technologies, Inc. VT8233 PCI to ISA Bridge
00:11.1 IDE interface: VIA Technologies, Inc. Bus Master IDE (rev 06)
00:11.2 USB Controller: VIA Technologies, Inc. UHCI USB (rev 1b)
00:11.3 USB Controller: VIA Technologies, Inc. UHCI USB (rev 1b)
00:11.4 USB Controller: VIA Technologies, Inc. UHCI USB (rev 1b)
00:12.0 Ethernet controller: VIA Technologies, Inc. Ethernet Controller (rev 70)
01:00.0 VGA compatible controller: ATI Technologies Inc Rage XL AGP (rev 27)
shyamal@rattler:~$ sudo /sbin/hdparm /dev/hda

/dev/hda:
 multcount    = 16 (on)
 I/O support  =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 7297/255/63, sectors = 117231408, start = 0
 busstate     =  1 (on)


Cheers!
Shyamal